This invention relates to the field of preparing, transporting and conveying fibrous, granular and other materials. The invention is described as it can be applied to the conveyance and application of fibrous insulation, such as acoustical or fireproofing insulation; however, the invention can be used in and with a large number of applications and materials. Some of the applications include pneumatic transport, conveyance, application and vacuum. Some of the material with which the invention can be used are grains, beads, shredded plastic, dust, fiberglass and other fibrous materials.
Fibrous insulation is typically applied to a desired surface by mechanically separating a quantity of the insulation from a bulk supply of the material, injecting the separated insulation into an airstream and, along with the airstream, through one or more tubes, pipes or conduits to the point of application, where it is sprayed or otherwise placed on the surface. The insulation must be injected into the airstream through an air lock to prevent the diversion of the airstream from the desired path and into the supply of insulation. Heretofore a paddlewheel type air lock typically has been used to inject the insulation into the airstream. The chambers of a paddlewheel air lock must be relatively large to allow the light insulation to fall into a chamber as it rotates. Additionally, a system using a paddlewheel air lock tends to inject the insulation into the airstream in a pulsed fashion, particularly at low revolutions.